pygccxml-development

[pygccxml-development] need help with query

[Roman Y. <rom...@gm...>]

I saw Matthias filters ( Or, Not and And ) and liked the idea. But (
there is always some 'but' :-( ).

I don't think they are useful in the form like this. People are to
lazy to learn. So instead
of composing queries using Matthias classes, they will right small
lambda function that will
do the job. May be I wrong, may be not. I propose an other
implementation. Take a look on attached file. Right now it does not
work. This is the area I need help. Can you see what I am doing wrong?

Lets say I have query class, that has __call__ method, that takes 1
argument - some text

qa =3D query_t( 'a' ) #returns true if 'a' in text
qb =3D query_t( 'b' ) #returns true if 'b' in text

qab =3D qa and qb
print 'a and b in text ac?', qab( 'ac' ) #False
print 'a and b in text ab?',qab( 'ab' ) #True

qaqb =3D qa or qb
print 'a or b in text a', qaqb('a') #True
print 'a or b in text b', qaqb('b')#True
print 'a or b in text c', qaqb('c')#False

Do you like such approach? Matthias what do you think?

Thanks for help.

--
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/

Re: [pygccxml-development] need help with query

[Matthias B. <ba...@ir...>]

Roman Yakovenko wrote:
> I saw Matthias filters ( Or, Not and And ) and liked the idea. But (
> there is always some 'but' :-( ).
> 
> I don't think they are useful in the form like this. People are to
> lazy to learn. So instead
> of composing queries using Matthias classes, they will right small
> lambda function that will
> do the job. May be I wrong, may be not. I propose an other
> implementation. Take a look on attached file. Right now it does not
> work. This is the area I need help. Can you see what I am doing wrong?
> 
> Lets say I have query class, that has __call__ method, that takes 1
> argument - some text
> 
> qa = query_t( 'a' ) #returns true if 'a' in text
> qb = query_t( 'b' ) #returns true if 'b' in text
> 
> qab = qa and qb
> [...]
> qaqb = qa or qb

The above lines should read:

qab = qa & qb
...
qaqb = qa | qb

"and", "or" is not the same as the &,| operators.

> Do you like such approach? Matthias what do you think?

I don't understand what problem you want to solve. Your query class just 
does the same than my filters, but above you say that this is too 
difficult to learn...? So in what respect is query_t easier to use than 
my filters?

- Matthias -

Re: [pygccxml-development] need help with query

[Roman Y. <rom...@gm...>]

On 3/15/06, Matthias Baas <ba...@ir...> wrote:
> Roman Yakovenko wrote:
> > I saw Matthias filters ( Or, Not and And ) and liked the idea. But (
> > there is always some 'but' :-( ).
> >
> > I don't think they are useful in the form like this. People are to
> > lazy to learn. So instead
> > of composing queries using Matthias classes, they will right small
> > lambda function that will
> > do the job. May be I wrong, may be not. I propose an other
> > implementation. Take a look on attached file. Right now it does not
> > work. This is the area I need help. Can you see what I am doing wrong?
> >
> > Lets say I have query class, that has __call__ method, that takes 1
> > argument - some text
> >
> > qa =3D query_t( 'a' ) #returns true if 'a' in text
> > qb =3D query_t( 'b' ) #returns true if 'b' in text
> >
> > qab =3D qa and qb
> > [...]
> > qaqb =3D qa or qb
>
> The above lines should read:
>
> qab =3D qa & qb
> ...
> qaqb =3D qa | qb
>
> "and", "or" is not the same as the &,| operators.
>
> > Do you like such approach? Matthias what do you think?
>
> I don't understand what problem you want to solve. Your query class just
> does the same than my filters, but above you say that this is too
> difficult to learn...? So in what respect is query_t easier to use than
> my filters?

By the way, I could be wrong. I just want a discuss this a little.

OrFilter and AndFilter takes as argument list of filters right. I
think that in most case
an user does not have more then 2 or 3 filters. I could be wrong. So I
think, user will not use next code

f1 =3D filter(....)
f2 =3D filter(...)

mb =3D module_builder_t(...)
mb.classes( OrFilter( [f1,f2] ) )

but rather:

mb.classes( lambda decl: f1(decl) or f2(decl) )

I could be wrong, but in this case he will not learn OrFilter. If we
implement your idea
in a different way, then user can write next line

mb.classes( f1 | f2 )

> - Matthias -

I hope, I was clear. I do like your idea, but I think it should be
improved a little.

--
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/

Re: [pygccxml-development] need help with query

[Matthias B. <ba...@ir...>]

Roman Yakovenko wrote:
> f1 = filter(....)
> f2 = filter(...)
> 
> mb = module_builder_t(...)
> mb.classes( OrFilter( [f1,f2] ) )
> 
> but rather:
> 
> mb.classes( lambda decl: f1(decl) or f2(decl) )
> 
> I could be wrong, but in this case he will not learn OrFilter. If we
> implement your idea
> in a different way, then user can write next line
> 
> mb.classes( f1 | f2 )

So you prefer this last line over the above two ways, right? I do agree 
with you and this is already how you can use my filter classes... :)

(By the way, as I see it, using the filter classes directly is already 
an advanced feature anyway. The "normal" user would just use the 
convenience arguments of the query methods (which are converted into 
filter classes internally))

- Matthias -

Re: [pygccxml-development] need help with query

[Roman Y. <rom...@gm...>]

On 3/15/06, Matthias Baas <ba...@ir...> wrote:
> > mb.classes( f1 | f2 )
>
> So you prefer this last line over the above two ways, right? I do agree
> with you and this is already how you can use my filter classes... :)

Ooooooooooops. It seems that I did not paid enough attention to your
classes (=3DFilterBase)
I just took a look on Or|And|Not Filters and did not understand why do
you need them.
Shame on me. I will add your classes to pygccxml.

Thank you very much. I am glad, that we talk.

> (By the way, as I see it, using the filter classes directly is already
> an advanced feature anyway. The "normal" user would just use the
> convenience arguments of the query methods (which are converted into
> filter classes internally))

Yes, but to write "mb.classes( f1 | f2 )" is cool.

> - Matthias -
>

Thank you very much.

--
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/